The project to remove a bottleneck on the East Coast Main Line at Hitchin will be used to test Network Rail’s plan to work more closely with contractors. Richard Johnstone reports.
Network Rail is to construct a new £60M flyover near Hitchin in Hertfordshire, to remove a key bottleneck on the East Coast Main Line (ECML). The viaduct will allow trains from London to cross the East Coast Main Line (ECML) and join the line to Cambridge without interfering with services between London, the North East and Scotland. Work is proceeding after the project won final planning approval on 30 March.
At present, services travelling from London to Cambridge via Hitchin must cross three ECML tracks via a series of points. This at grade junction inevitably causes congestion on both lines. The new flyover will take services above the ECML removing the bottleneck and increasing capacity.
The new 2.3km flyover will run partly on embankment and partly on viaduct from a point to the north of Hitchin station to a point on the existing Hitchin to Cambridge railway.
The scheme has been in development since Railtrack’s days. Neil Kelsall, project manager for the project’s lead engineering designer Arup says he first got involved in 1997, and worked on options in those early stages.
Hitchin is a “key location” capacity constraint on a line, which is expecting 2% annual growth over the next 10 years. According to Network Rail, the current set up “renders it impossible to accommodate additional long distance high speed services on the line without increased journey times.
This will become possible with the construction of the 850m long viaduct, which will be constructed of steel beams with an insitu concrete deck. Positioning the 850m long viaduct across the ECML, represents one of the challenges of the project. This will likely require “a small number” of railway possessions to get the main span in place.
There is also the challenge of moving the 300,000t of material that will be needed to create the approach embankments. “Getting that to site is a contractor challenge, and through the course of the public inquiry to gain planning consent for the scheme, the impact of importing that material via public roads was one of the key areas of objection,” Kelsall says.
The scheme is the first to be undertaken under the track operator’s new contractor strategy, where alliances are to be formed with contractors to deliver projects more efficiently. The idea is that any cost savings are then shared. Kelsall says that the multi-disciplinary nature of the Hitchin scheme means it will be a “good example” of the type of project on which the new way of working can be tested.
Advance works on the project, including the strengthening of roads to take the weight of embankment fill, will begin this year, and a contractor is likely to be appointed in August.
The appointed contractor will then complete the detailed design before work starts at the beginning of next year. The project is due for completion in late 2013.
Hitchin is the first of seven projects that will be taken forward under Network Rail’s new contracting strategy. This aims to reduce costs and generate better value by opening up Network Rail’s biggest rail projects and programmes to construction and engineering companies at an early stage.
Early involvement will see suppliers fully integrated into Network Rail’s delivery teams in a joint venture. Opening up schemes to suppliers in this way will lead to projects being delivered faster, more safely and more efficiently, Network Rail claims.
The strategy’s other projects are:
- The Edinburgh to Glasgow improvement programme
- The Thameslink project’s redevelopment of London Bridge
- High-output delivery of the Great Western electrification scheme
- National major resignalling project
- The Birmingham Gateway redevelopment of New Street
Network Rail’s civils renewal programme.